Here's a place where I can post my thoughts on new papers, provide updates on my projects, and post info that will eventually be on my website The Theropod Database - http://theropoddatabase.com/ . It will center on theropods, but may delve into other topics as well such as phylogenetics.

Tuesday, February 22, 2011

Figure I have these things written, might as well post them. Today we finish off the sauropods. Remember the references not listed are in the first Zhao nomen nudum post.

"Megacervixosaurus" Zhao, 1983

"Megacervixosaurus tibetensis" Zhao, 1986Etymology- The genus name refers to a large neck, while the species name refers to Tibet where the remains were found. Late Cretaceous
Zonggu Formation, Zonggu, Markam County, Tibet, China
Material- specimen including cervical vertebrae
Comments- Zhao (pers. comm. in Molnar, 2011) noted similarity of its posterior cervicals to Austrosaurus.Relationships- Stated by Zhao (1983) to be a homalosauropodoid, in which he includes peg-toothed taxa like diplodocoids and titanosaurs. Lambert (1990), Olshevsky (1991) and provisionally Glut (1997) listed it as a diplodocid.Olshevsky (online, 1999) also suggested it may be mamenchisaurid, perhaps based on the name, though Zhao did place Mamenchisaurus in Homalosauropodoidea too .Weishampel et al. (2004) questioningly listed it as a lithostrotian. As no morphological data has been released on "Megacervixosaurus", its relationships must necessarily remain tentative.The absence of Cretaceous or Asian diplodocids renders that identification suspect, while mamenchisaurids are also unknown from the Cretaceous.Indeed, the only Late Cretaceous sauropods are rebbachisaurids and titanosaurs, and only the latter are known from East Asia."Megacervixosaurus" is here considered a probable titanosaur.References- Yang, 1986. The Cretaceous System. in Yang, Cheng and Wang (eds.). The Geology of China. Clarendon Press. 153-167. Zhao,1986. [unknown title] in Hao, Su, Yu and Li (eds.). The Cretaceous System of China. Stratigraphy of China. 12, 67-73. Molnar, 2011. New morphological information about Cretaceous sauropod dinosaurs from the Eromanga Basin, Queensland, Australia. Alcheringa: An Australasian Journal of Palaeontology. DOI: 10.1080/03115518.2011.533978

Comments- The species name is spelled "wudingi" in the text, and "utingensjs" in the figure caption, which as noted by Chure and McIntosh (1989) are probably unintentional variants, and the latter no doubt a mispelling of "utingensis". The skeleton was discovered by Su in 1954, but the dentaries were only discovered later in 1960 and described and illustrated by Young (1966) as specimens of Lufengosaurus magnus. Dong (1992) referred them to the same individual as the postcrania since they came from the same quarry. While Dong (and later Olshevsky, 2000) was incorrect in stating Zhao described the taxon in 1985, his own book contains a diagnosis, type and illustration so would seem to validate the nomenclature (contra Barrett, 1999). Indeed, Upchurch et al. (2004) attribute the name to Dong, 1992. A photo of part of the mounted skeleton is in Zhao (1985), contra Barrett (1999). Dong et al. (1990) published a photograph of the entire skeleton, and several are available online as well. Li et al. (2010) note Kunmingosaurus lacks dorsal pleurocoels and has a poorly developed fourth trochanter. Simmons (1965) described a maxilla (FMNH CUP 2042) from Ta Ti in the same beds as Yunnanosaurus robustus, which is similar to Kunmingosaurus in having a sauropodan lateral plate and serrated, spatulate teeth with a lingual ridge.Barrett (1999) redescribed it as a sauropod maxilla, though he did not refer it to any genus.Upchurch and Barrett (2000) described a referred tooth.
Relationships- Stated by Zhao (1985) to be a primitive sauropod.Chure and McIntosh (1989) and Lambert (1990) listed it as a cetiosaurid, while Olshevsky (1991) listed it provisionally as a barapasaurid and Dong (1992) as a shunosaurine camarasaurid. Upchurch and Barrett (2000) discussed it as a 'vulcanodontid', which was a grade of basal sauropods in their scheme, and described a referred tooth.Upchurch (1995) noted there was no published evidence suggesting it was a vulcanodontid, however.He later (1998) noted that Kunmingosaurus' teeth were more plesiomorphic than Barapasaurus, Shunosaurus, Patagosaurus and other taxa in having only a shallow lingual concavity and being quite labiolingually compressed.Barrett (1999) considered the dentaries to be sauropod based on the dorsoventrally expanded symphysis and lateral plate. Fang et al. (2006) list it as a camarasaurid. When entered into a modified version of Wilson's (2002) analysis, Kunmingosaurus emerges more derived than Chinshakiangosaurus, Antetonitrus, Lessemsaurus and Blikanasaurus but less thanShunosaurus and eusauropods (so is not a cetiosaurid, barapasaurid, shunosaurid or camarasaurid).It is thus related to taxa such as Gongxianosaurus, Kotasaurus, Spinophorosaurus, Tazoudasaurus and Vulcanodon, so may be considered vulcanodont-grade.Note the results agree with Upchurch's (1998) statements, though his dental characters were not used by Wilson.Specifically, Kunmingosaurus is more derived than Chinshakiangosaurus based on the D-shaped teeth and reduced fourth trochanter, but less derived than Shunosaurus based on no crown-to-crown occlusion, straight dorsal ilial margin and unreduced pedal phalanges.

Wednesday, February 16, 2011

Just wanted to reassure everyone I'm still here. I've been doing *gasp* actual work to be submitted, finishing off the last appendix of the manuscript. But in the absence of something else, here's a Photoshop rendition of Megaraptor's metatarsus using the holotype (metatarsal III, from Novas, 1998), MUCPv-341 (metatarsal IV, from Calvo et al., 2004) and UNPSJB-PV 958 (metatarsal II, from Lamanna, 2004). The individuals are almost the same size based on their manual unguals Is, so the metatarsals are at almost the same scale.